1. Field of the Invention
The present invention relates to auxiliary devices for bicycles, and more particularly to an auxiliary device that thrusts and is thus driven by a cyclist's back thighs to assists in driving treadles when the cyclist rides the bicycle, wherein the auxiliary device moves synchronously with the cyclist's downward moving thighs and shanks, so as to reduce burden bore by the cyclist's front thigh muscles and shank muscles, thereby facilitating progression.
2. Related Art
Bicycles are popular for being not only a transportation means but also an exercise tool. A cyclist rides a bicycle forward by exerting downward force on treadles of the bicycle to drive wheels through the bicycle's chain. During such riding, the cyclist has his/her front thigh muscles (quadriceps) and shank muscles exercised most, and fatigue accumulated in these muscles over time tends to deteriorate the cyclist's riding endurance and speed.
It is well known that thigh muscles are the most sinewy muscles in human bodies. With this understanding, the present inventor believes that by thrusting a cyclist's back thigh muscles when the cyclist treadles a bicycle's treadles, the fatigue otherwise accumulated in the cyclist's front thigh muscles and shank muscles can be reduced, and force exerted by the downward moving thighs can be used as additional motive power.